Building Multipoint Pseudo Wires Using a Multipoint Label Distribution Protocol (mldp)

1. A method of building multipoint Pseudo Wires (PWs) using Multipoint Label Distribution Protocol (MLDP) comprising: configuring a multipoint PW leaf identifier (mTAI) on at least one Layer 2 (L2) leaf interface of a multipoint PW; providing a multipoint PW root identifier identifying a root provider edge (PE) router of the multipoint PW; computing an opaque value used in MLDP label mapping messages that will flow upstream towards the root of the multipoint PW, said opaque value computed from said multipoint leaf identifier and said multipoint PW root identifier; and directing, by PE leaf routers, MLDP label mapping to the root PE router via a core network.

2. The method of claim 1 further comprising replicating of PW encapsulated L2 packet data units (PDUs) at branch points of a tree including the root of the multipoint PW.

3. The method of claim 2 further comprising installing a unique state containing an opaque value for each multipoint PW by core routers.

4. The method of claim 3 further comprising installing one opaque value state for each multipoint PW on PE and core routers along the tree.

5. The method of claim 1 wherein said multipoint PW root identifier comprises one of a group consisting of an IP address of the root PE router, and a value identifying an ingress L2 interface on the root PE router.

6. The method of claim 1 further comprising configuring a root PE router with the multipoint PW leaf identifier (mTAI) on the inbound interface receiving the L2 packet data units (PDUs) from the actual source.

7. The method of claim 6 further comprising receiving an MLDP label mapping by the root PE router and using the opaque value to associate the multipoint PW with the ingress L2 interface.

8. The method of claim 2 wherein said replicating of PW-encapsulated L2 PDUs at branch points of a tree including the root of the multipoint PW comprises receiving L2 PDUs at the ingress L2 interface of the root router, imposing a multipoint PW label, and forwarding down the tree to all interested PE leaf routers and their respective L2 leaf interfaces.

9. The method of claim 1 wherein said multipoint PWs comprise multi-source multipoint PWs, and wherein each root and PE leaf router of the multipoint PW are configured with a same mTAI value on interface(s) that the L2 packet data units (PDUs) are communicated on.

10. The method of claim 9 further comprising building a multipoint to multipoint (MP2MP) LSP towards a root of the tree, the MP2MP LSP providing a loop free distribution tree between PEs.

11. The method of claim 1 wherein said multipoint PWs comprise one of the single-source PWs and multi-source multipoint PWs, and wherein a default multi-source multipoint PW is built.

12. The method of claim 11 further comprising forwarding multicast control packets on the default PW.

13. The method of claim 11 further comprising snooping protocol independent multicast (PIM) and internet group management protocol (IGMP) packets and producing a unique PW tree for each multicast group.

14. The method of claim 12 further comprising computing an mTAI using a media access control (MAC) address of the multicast group of interest, said mTAI serving as the opaque value in MLDP label mapping to create a separate multipoint PW tree per MAC address.

15. The method of claim 14 further comprising joining a same PW tree in the core by each PE router that is interested in the same MAC address.

16. The method of claim 15 further comprising receiving, by a root PE router, the MDLP label mapping, decoding MAC address from the opaque encoding and determining which packets to forward on the PW.

17. A non-transitory computer readable medium having computer readable code thereon, which when executed by a processor implements building multipoint Pseudo Wires (PWs) using Multipoint Label Distribution Protocol (MLDP), the non-transitory computer readable medium comprising: instructions for configuring a multipoint PW leaf identifier (mTAI) on at least one Layer 2 (L2) leaf interface of a multipoint PW; instructions for providing a multipoint PW root identifier identifying a root provider edge (PE) router of the multipoint PW, wherein said multipoint root identifier comprises one of the group consisting of an IP address of the root PE router, and a value identifying an the ingress L2 interface on the root PE router; instructions for computing an opaque value used in MLDP label mapping messages that will flow upstream towards the root of the multipoint PW, said opaque value computed from said multipoint leaf identifier and said multipoint PW root identifier; instructions for directing, by PE leaf routers, MLDP label mapping to the root PE router via a core network; instructions for replicating of PW-encapsulated L2 packet data units (PDUs) at branch points of a tree including the root of the multipoint PW, said replicating comprising receiving L2 PDUs at the ingress router, imposing the multipoint PW label, and forwarding down the tree to all interested PE leaf routers and their respective L2 leaf interfaces.

18. The non-transitory computer readable medium of claim 17 further comprising: instructions for installing a unique state containing an opaque value for each multipoint PW by core routers; instructions for installing one opaque value state for each multipoint PW on PE and core routers along the tree; instructions for configuring a root PE router with the multipoint PW leaf identifier (mTAI) on the inbound interface receiving the L2 PDUs from the actual source; and instructions for receiving an MLDP label mapping by the root PE router and using the opaque value to associate the multipoint PW with the ingress L2 interface.

19. The non-transitory computer readable medium of claim 17 wherein said multipoint PWs comprise multi-source multipoint PWs, wherein each PE router of the multipoint PW is configured with a same mTAI value on an interface PDUs are communicated on, said medium further comprising instructions for building a multipoint to multipoint (MP2MP) label switched paths (LSP) towards a root of the tree, the MP2MP LSP providing a loop free distribution tree between PE's.

20. The non-transitory computer readable medium of claim 17 wherein said multipoint PWs comprise one of single-source PWs and multi-source multipoint PWs, wherein a default multi-source multipoint PW is built between PE routers, said medium further comprising instructions for forwarding all the multicast control packets, and instructions for snooping protocol independent multicast (PIM) and internet group management protocol (IGMP) packets and producing a unique PW tree for each multicast group.

21. The non-transitory computer readable of claim 20 further comprising instructions for computing an mTAI using a media access control (MAC) address of the multicast group of interest, said mTAI serving as the opaque value in MLDP label mapping to create a separate multipoint PW tree per MAC address, instructions for joining a same PW tree in the core by each PE router that is interested in the same MAC address, and instructions for receiving, by a source PE router, the MLDP label mapping, decoding MAC address from the opaque encoding and determining which packets to forward on the PW.

22. A network system comprising: a memory; a processor; a communications interface; an interconnection mechanism coupling the memory, the processor and the communications interface; and wherein the memory is encoded with an application that when performed on the processor, provides a process for building multipoint Pseudo Wires (PWs) using Multipoint Label Distribution Protocol (MLDP), the process causing the network system to be capable of performing the operations of: configuring a multipoint PW leaf identifier (mTAI) on at least one Layer 2 (L2) leaf interface of a multipoint PW; providing a multipoint PW root identifier identifying a root provider edge (PE) router of the multipoint PW, wherein said multipoint root identifier comprises one of the group consisting of an IP address of the root PE router, and a value identifying an ingress L2 interface on the root PE router; computing an opaque value used in MLDP label mapping messages that will flow upstream towards said one of the group consisting of a source of the multipoint PW and a root of the multipoint PW, said opaque value computed from said multipoint leaf identifier and said multipoint PW root identifier; and directing, by PE leaf routers, MLDP label mapping to the root PE router via a core network; replicating of PW-encapsulated L2 PDUs at branch points of a tree including a root of the multipoint PW, said replicating comprising receiving L2 packet data units (PDUs) at the ingress L2 interface of the root PE router, imposing the multipoint PW label, and forwarding down the tree to all interested PE leaf routers and their respective L2 leaf interfaces.

23. The network system of claim 22 wherein said multipoint PWs comprise multisource multipoint PWs, wherein each PE router of the multipoint PW is configured with a same mTAI value on L2 interface(s) PDUs are communicated on, wherein a multipoint to multipoint (MP2MP) label switched path (LSP) is built towards a root of the tree, the MP2MP LSP providing a loop free distribution tree between PE's.

24. The network system of claim 23 wherein said multipoint PWs comprise one of a group consisting of single-source PWs and multi-source multipoint PWs, wherein a default multi-source multipoint PW is built, wherein multicast control packets are forwarded on the default multi-source multipoint PW, and wherein the PE routers snoop protocol independent multicast (PIM) and internet group management protocol (IGMP) packets and produce a unique PW tree for each multicast group.